A road milling machine includes a plurality of ground engaging members supporting a machine frame of the road milling machine. The ground engaging members may include wheels or tracks, and may be connected to the machine frame through lifting columns. The lifting columns allow independent adjustment at each corner of the machine frame to facilitate various orientations of the machine frame relative to a ground surface to be treated, such as, for example, a paved surface. A rotor is supported by the machine frame and oriented perpendicularly relative to a longitudinal centerline of the road milling machine for treating or, for example, milling the paved surface. Typically, height adjustable side plates are positioned at opposite side ends of the rotor and define outer walls of the road milling machine. The side plates rest on the paved surface being treated and, thus, are raised relative to the machine frame as the machine frame is lowered during the milling process.
Due to the close proximity of the side plates to the rotational axis of the rotor, position sensors are often positioned to measure vertical movement of the side plates relative to the machine frame, or one another, to arrive at a milling depth, and/or inclination, of the rotor. Although acceptable in most circumstances, the measurements obtained by these position sensors may be inaccurate in particular scenarios. For example, when milling an edge of the paved surface being treated, one of the side plates may rest on an unpaved surface, which may include grass, rocks, or soil, rather than the paved surface. As such, the calculated milling depth at the edge may be inaccurate and may necessitate measurements by hand during the milling operation.
Wirtgen GmbH, a company headquartered in Windhagen, Germany, offers hydraulic milling depth sensors that capture the level on the sides and in front of a milling drum, as shown in the Wirtgen publication page submitted herewith. In particular, the Wirtgen hydraulic milling depth sensors positioned inboard relative to side plates flanking the milling drum appear to be supported near the ground surface by a pair of pivotably connected linear arms. Although the inboard hydraulic milling depth sensors of Wirtgen may provide one solution to the edge surface treatment problem described above, there is a continuing need to provide highly accurate sensors and sensor mounting arrangements for calculating milling depth.
The present disclosure is directed to one or more of the problems or issues set forth above.